Yeoman
https://stackoverflow.com/questions/19485806/what-does-mean-in-paths-of-gruntfile-js
What does `{,*/}` mean in paths of Gruntfile.js?
watch: { styles: { files: [ '<%= yeoman.app %>/styles/{,*/}*.less' ], tasks: ['copy:styles', 'autoprefixer'] } }
This pattern is widely used in yeoman templates: it means to look only one level deep inside folder hierarchy. It is used mostly for performance reasons since watching too many files simultaneously can be slow (or even impossible).